Well it seems there is a bug when you set stepsize for Scroll Bars to be 1, it ignores them and steps in 0.01 (Photoshop CC 2015).
I wist there was a slider which jumps over integers (With the Ticks at the bottom).
Moreover, I didn't understand from there how set the Drop Down List names and how to extract which value was selected.
I'm not sure about the scroll bars, as I don't use them. However, for the dropdownlist, you want to define an array with the list of items you want in your list. Getting the value varies, you can get either the text value or the array value. I tend to use the array value, so when you write the code to get the value, you want to define the returned value as a number using parseInt.
var dropListArray = ['one','two','three']; //code here to define you UI first dlg.dropList = dlg.add('dropdownlist',undefined,dropListArray) //to set the drop list: dlg.dropList.selection = 0 //To get the value of a selection: var dListValue = parseInt(dlg.dropList.selection)//gets array value var dListValue = dlg.dropList.text//gets the text value.